Small-structured, automotive working devices for soil compaction of the afore-mentioned type are controlled by one operating person who walks with the working device. The operator steers the device in the direction of movement and controls the device functions by means of a guide lever. The guide lever is usually designed as a height-adjustable drawbar. The control and operating elements are arranged on the head of the drawbar.
Since vibrations emanate from such working devices, particularly dynamic compacting machines, the guide levers must be designed to be vibratory damped. The use of elastic materials for this purpose, preferably the use of the so-called rubber-metal combinations has proved to be advantageous. Such elements have good damping characteristics particularly in the case of shearing loads.
Known design forms of the combinations of the working device and the guide lever load the damping elements preferably in the axial direction. The overlaying stress that is mostly present (pressure, shearing, torsion) is not suitable for achieving good damping characteristics.
Also another arrangement is known in which the damping elements are arranged coaxial to each other. Here the guide lever is connected via an intermediate component to both the damping elements. However, the disadvantage of the layout that provided technical protection from vibrations is that the steering efforts have to be transferred to the working device via the damping elements and this essentially leads to increased stresses.
In accordance with a suggestion in CH 426 660 a metallic component should be additionally inserted below the damping equipment in such an arrangement. The metallic component should be able to accommodate the guide lever (drawbar) in a slot-shaped recess. In order to transfer steering efforts in such an arrangement the guide lever leans against the side surface of the recess and transmits the steering efforts directly. The disadvantage is that during the application of steering forces the decoupling of the vibrations of the working device is adversely affected. Other disadvantages are the additional guide component increases the costs of the device and works only in a limited angular range.
The combination of the guide lever with the damping elements simultaneously forms the setting device for the guide lever. For a desirable adjustment of the setting angle of the guide lever to ergonomic conditions it is necessary to detach the fixed connection of the guide lever to the damping elements and to reattach it after readjustment. Otherwise an adjustment of the position is possible only in the corresponding length of the guide lever by applying external forces and the consequent torsion of the damping elements. The existing technical conditions call for either an optimized layout in relation to the vibration damping or an increased mobility of the guide lever.